Production of metallic tungsten.



FREDERICK G. KEYES, 0F CAMBRIDGE, MASSACHUSETTS, ASSIGNOR TO COOPERHEWITT ELECTRIC COMPANY, OF HOBOKEN, NEW JERSEY, A CORPORATION OF NEW JERSEY.

PRODUCTION OF METALLIC TUNGSTEN.

Specification of Letters Patent.

Patented Feb. 4, 1919.

No Drawing. Original application filed February 11,1914, Serial No.818,008. Divided and this application filed July 11, 1917.

T 0 all whom it may concern:

Be it known that I, FREDERICK G. Knms, a citizen of the United States,and resident of Cambridge, county of Middlesex, State of Massachusetts,have invented certain new and useful Improvements in the Production ofMetallic Tungsten, of which the following is a specification.

The present method of obtaining metallic tungsten consists in adding totungsten trioxid (W0 a suitable binding material, and then reducing inan atmosphere of hydrogen at a high temperature. The ingot thus producedconsists of metallic tungsten cemented together by a binding materialand the next step in the'process is that of subjecting the ingot to aswagin process which is also carried out at a hig temperature. Theswaging is continued until the ingot is reduced to a diameter thatpermits of its being drawn while hot through suitable dies until thedesired sizes are obtained. The binding material is so selected as totoughen the resulting wire. 7 It is a disadvantage appertaining to thisprocess that the dies are lubricated with graphite. It is a matter ofcommon knowled e that tungsten has a great avidity for car on, whereasit would be an advantage to prevent, if possible, any cementation. Thisis done in the above mentioned method of obtaining tungsten and theresult is that the tungsten wire used in tungsten lamps is in realitynot a pure metal, but a mixture,

chemical or otherwise, of binding material Serial No. 179,934.

used, or, preferab y it may in the early stages of the drawing be drawnthrough dies of a special tungsten-iron-carbon alloy. Such alloys arealready known in the arts and tools made ofit hold their edge at a redheat. The pure tungsten havmg, as

stated, a superior quality of ductility when obtained by my process maybe drawn through these special dies, thus avoiding the expensive dlamonddies. As a lubricatin material powdered talcum may be substituted forthe deleterious graphite.

This application is a division of my application Serial Number 818,008,filed February 11th, 1914.

I claim as my invention:

1. The method of obtaining pure metallic tungsten which consists informing a solution of tungsten in boric acid and electrolyzing thesolution thus formed.

2. The method of obtaining pure metallic tungsten which consists indissolving tungsten in boric acid at approximately 1200 to 1400 C. andelectrolyzing the solution thus formed.

3. The method of obtaining tungsten, which consists in forming asolution of tungsten compound in an ionizing medium and electrolyzingthe solution thus formed.

4. The method of obtaining tungsten, which consists in dissolvingtungsten compound in an ionizing medium at approximately 1200 to 1400centigrade and electrolyzing the solution thus formed.

Signed at Cambridge, in the county of Middlesex and State ofMassachusetts, this 9th day of July, A. D. 1917.

' FREDERICK c. KEYEs.

Witnesses:

ALTER HUMPHREYS, Wrrmmrvr daemon.

